TO-20 stumper

[Anonymous-0]

To start out, since I bought my 1951 TO-20 here is what I have done to it:

- replaced water pump
- rebuilt carb
- changed points & condenser
- changed coil
- changed plugs
- changed battery (it is 12V system)
- changed engine oil

My Fergie came with a 60" Woods finish mower that I'm trying to cut about 5 acres with and although it's not a "lawn" yet, I've been trying to keep up on it so it doesn't bog it down too much.

So on to my latest stumper.... when I start her up she fires first crank and idles fine for about 10 seconds and then begins lopping and erratic misfiring, sputtering black clouds of smoke as it chugs. The more throttle you give it the hard it chokes, it won't die out but doesn't have enough power to even get out of the barn. I figure it has to be something with the fuel but have played with the carb settings, cleaned the sediment bowl and fuel line, and drained the gas tank. My brand new plugs are already cked in black soot, I clean them, put them back in and let it idle for another minute and they're back to black..... can someone help me please?! I'm out of ideas...

 

[KSTractor]

Have you checked the air cleaner?

 

[buckeyepost]

(quoted from post at 04:48:02 08/19/09) Have you checked the air cleaner?

This is Jerry P, I just registered.... I haven't looked in the air tube but that would make sense. I added oil and the screen looked clean. I guess I could just pop the ait intake off of the carb and see if it runs better, that would tell me if it was intake related, right?

 

[Jeff-oh]

When my TE has a power loss issue it usually means I left the choke on. Have you checked your carb settings?

The power jet(large screw) should be screwed out ~1-1/4 turns but no less than 1 full turn. As you said you rebuilt the carb.

If that does not do it you may need to check your timing, as you changed the points. Should be set 7 degrees BTDC. There is a timine hole plug near the starter.

 

[Jeff-oh]

BTW are you a fellow Ohioian?

 

[buckeyepost]

I actually never even choke it to start, just a little throttle is good enough. And I have tried everything from 1 1/4 - 2 1/2 on the carb needle. After I changed the points it ran well for 3-4 hours and then it sat for 3 weeks and that's when I began having problems. I did twist the distributor a tiny bit to change timing but nothing worked so I put it back to it's original location that I marked. Other than that I've never tried to change timing the right way. And yes, I am in Granville, Ohio. Thanks for the input!

 

[mwferg]

I just got finished with the same problem on my TO20. Ift ran fine until it warmed up, then it loped and barely ran. The problem was the new condenser that I had just installed with the point set. I finally put the old condenser on, and it mowed the whole 7 acres without a stumble. The new condenser was breaking down (shorting) when it got warm. Maybe those foreign parts aren't what they are cracked up to be......mwferg

 

[buckeyepost]

(quoted from post at 05:53:20 08/19/09) I just got finished with the same problem on my TO20. Ift ran fine until it warmed up, then it loped and barely ran. The problem was the new condenser that I had just installed with the point set. I finally put the old condenser on, and it mowed the whole 7 acres without a stumble. The new condenser was breaking down (shorting) when it got warm. Maybe those foreign parts aren't what they are cracked up to be......mwferg

Hmmmm, very interesting.... is there a way to use the new points with the old condenser?

 

[johnandcindy1981]

Double check the wires on the plugs to the distributer the firing order is on the side of the block. It sounds like there are wires crossed. Like Jeff wrote adjust the power valve 1 and 1/4 open. There are some smart folks on this site you will find the problem.
Regards, John

 

[buckeyepost]

Thanks John, I did check the plug wire locations last night, compared them to the block and my TO-20 manual.

 

[Dan S (NY)]

Yes, check it with the air intake tube removed. Also, make sure your carb float is not set to high or sticking.

Dan

 

[buckeyepost]

I'm not sure about the float height b/c I didn't rebuild it, an old pro did it. But, I did get the advice to tap the carb with a rubber mallet to possibly free a stuck float but that didn't do anything.

 

[semlin]

if it ran well for 3-4 hours before then to start with i would stick to things that could go bad while it is sitting. to me that means carb passages -- you might have dislodged some deep grit when you were running. if you remove the intake tube from the carb and then run it, see if any fuel pours out of the choke intake if you leave the fuel turned on for a while which would be a float adjustment. from the black soot on the plugs it sounds like you are flooding or have a fuel obstruction. i think you need to take the carb apart and blow and wire everything out and make sure the float needle is disengaging properly and the float is not set less than 1/4".

 

[buckeyepost]

This is all good advice, I hope to get out to it again soon to try some of these things.

Last night I also took the needle and drain plug out and sprayed some carb cleaner up in there... again, no difference.

 

[Jerry/MT]

Generally a clogged air cleaner will limit the max power and not effect the mixture since the M-S carb is a pressure balanced design. The exception is a 100% blocked aircleaner and that's a real longshot occurence.

Is your timig and firing order correct and do you have the requisite FAT, BLUISH-WHITE SPARK, the color of lightning? Is the ignition timing advance working?
If the ignition all checks out, I'd suspect an overly rich mixture setting on the carb or too high a float setting on the carb. The initial mixture should be set at 1-1/4 turns open from full closed and no less that one full turn open. Your idle mixture actually controls the idle airflow and so it works bass ackwards. When you screw it in, it enriches the mixture. Try an initial setting at 3/4 turn out. If mixture settings don't help, then you have to check the float level and that means the carb has to come off.

 

[buckeyepost]

Jerry, I believe you have helped me before on another forum! Firing order and spark are good but I'm not sure if I know how to check the ignition timing advance.

 

[dagger dog]

Jerry,

Blacksmoke, especially clouds of it usually designates too rich a mixture, too much fuel,or not enough air.

The engine starting immediatley kind of rules out anything in the timing being off, if the timing was set wrong, the problem would usually be evident on the inital start. Same goes with the firing order, its kind of hard to get a 4 cyl inline engine to run with any kind of stability if the timing or firing order was off.

If it is a carb problem try this out. Make sure the choke butterfly isn't stuck shut.

The engine needs a little extra fuel to start run even if the ambeint temperature is warm, 70 degrees F or warmer, so the way your tractor is acting the engine starts right up and the extra fuel is used until it the engine warms and it can't use the extra fuel and then it starts the stumbling and " choking out" thats the black smoke you see.

There are several circuts within the carb, one for idle, one for mid throttle, and one for wide open throttle. See what happens when you full throttle the carb. Some of that extra fuel its getting should be used up under full throttle and it should run a little smoother at full throttle with a little less black smoke. If this is the fact I would certianly look at the float levels as suggested in the previous post, plus look at the primary air bleed circut, the very small holes in the primary air bleed jet and elmulsion tube can easily plug from the slightest debris.

Some older carbs plug up so bad they have to be soaked overnight in cleaning soultion, and even then are very hard to get those passeges clean. The jets can be cleaned ,if they can be removed, with small peices of copper wire stripped from various sizes of automotive primary wire.

Black smoke = too rich air fuel ratio!

 

[buckeyepost]

Not sure if that picture came through.... but, is the air bleed jet the little tiny thing towards the bottom of the carb next to the drain plug? I don't have my manual to refer to right now, just trying to know what you're talking about. And, I agree... it has to be something with too much fuel at this point.

Oh, and more throttle just chokes it more. Sometime to the point that it stalls. Basically, fewer but more powerful sputters, make sense?

 

[JMOR]

(quoted from post at 16:45:05 08/19/09)

Not sure if that picture came through.... but, is the air bleed jet the little tiny thing towards the bottom of the carb next to the drain plug? I don't have my manual to refer to right now, just trying to know what you're talking about. And, I agree... it has to be something with too much fuel at this point.

Oh, and more throttle just chokes it more. Sometime to the point that it stalls. Basically, fewer but more powerful sputters, make sense?

No that is not your air bleed. It can only be accessed by splitting the carb top from bowl.

 

[Jerry/MT]

Engines with retarded timing will often start easily but not run well at higher rpms under load. The TO-20 should have timing at 7 oBTC. they'll star and idle witha more retarded spark.

I'm merely trying to help the user eliminate the ignition system as a source of the problem. Weak sparks will cause fouled plugs. I generally start by advising people to make sure that the ignition system is in correct order before they start futzing with the carb. The ignition system is the source of most of the problems with these old engines.

If you read my entire post you'll note I went on to the carbureton after the ignition system. You'd be surprised how may people run engines with the firing order incorrect. I don't recall the poster saying there was black smoke but he did say his plugs were fouling relatively quickly.

Thanks for your comments on my post.

 

[Jerry/MT]

Engines with retarded timing will often start easily but not run well at higher rpms under load. The TO-20 should have timing at 7 oBTC. they'll start and idle with a more retarded spark.

I'm merely trying to help the user eliminate the ignition system as a source of the problem. Weak sparks will cause fouled plugs. I generally start by advising people to make sure that the ignition system is in correct order before they start futzing with the carb. The ignition system is the source of most of the problems with these old engines.

If you read my entire post you'll note I went on to the carbureton after the ignition system. You'd be surprised how may people run engines with the firing order incorrect. I don't recall the poster saying there was black smoke but he did say his plugs were fouling relatively quickly.

Thanks for your comments on my post.

 

[Jerry/MT]

You need a timing light. You merely check the initial timing at low rpm (7 oBTDC 400 rpm is the spec)and then advance the throttle and watch the timing advance as the engine rpm increases. the Spec says that the spark should advance to 21 oBTDC at 1000 rpm and 31 oBTDC at 2000 rpm.

 

[Jerry/MT]

After re-reading the origina;ost. I did find the reference to black clouds of smoke.

 

[buckeyepost]

Thanks guys! My name is Jerry too, so dagger is probably talking to me. The timing light ordeal sounds like more than I know to do. But I have been pointed in that direction by a few people. Would that still cause the plugs to foul so quickly?

This is really great for me guys! I don't have anyone else to turn to for knowledge on my tractor. I really do appreciate all the help!

 

[buckeyepost]

Looking back at these posts it is kinda confusing! With two Jerry's etc. Just to clear things up, I am the original poster, I just had to register in order to respond and I use buckeyepost as my username on other forums... so, [b:e3f331db65]buckeyepost=Jerry P.[/b:e3f331db65]

 

[dagger dog]

buckeye,

JerryMT's advice is valid and should be heeded, to make sure that is not causing some problems, and Jmors post stating about splitting the carb to gain acess to the main air bleed is correct.

The carb on my TO35 is the Marvel, and I know they have a 4 Meg download of info on the carb at theoldfergusontractor resource site.

The basic concept is the same throughout the older fixed venturi style carbs. looking at my parts manual they list what I call the main air bleed as nozzle assembly fuel, and another area to check is the idling jet. This is on the breakdown of the Carter carb for the TO35 but would be similar to your carb.

Also the main needle and seat which is supposed to shut of the fuel when the carb bowl is full, then maintain that level, should be checked, this is the float level adjustment and is the same concept as the bowl at the back of a toilet, the float drops and lets in more water( fuel ) as the demand becomes greater. Make sure the float is not "sunken" some times they are made hollow and if it has a hole in it can fill with fuel and sink too far down in the bowl, opening the needle and seat and letting in more fuel than needed.

If you can find a breakdown of the carb you can locate the jets and clean them with the copper wire strands stripped from waste wiring. While the bowl is open pour it full of a good grade carb cleaner, I like the GM Goodwrench TOP CLEANER available through the GM parts depts.

Remove the jets clean them, then plug the openings in the bowl and pour it full of the top cleaner and let it set over night, then use a can of aerosol carb cleaner with the little wand and blow through each passage from where you removed the jets, from both ends of the passages. You will blow the aerosol through one end and you should see a good spray coming from the venturi area in the center of the carb, thats where the air and fuel are mixed to the correct proportions . If you have compressed air available use it to give the passages a final blast to make sure they are clean.

There is usually a spacer type washer under the main fuel inlet needle and seat and is used to help maintain the correct float height, some times it is not installed and can cause problems.

Hope I am helping and not confusing. There are many on this site that know much more than myself and I'm sure they are willing to help you work this problem out.

 

[buckeyepost]

Thanks again guys! I'm heading out to my property here after work to tinker with it a little. I printed off the carb photos/info... I'll report back tomorrow!!

 

[buckeyepost]

No luck..... I didn't take the carb apart b/c when it was rebuilt 2 months ago it soaked for 3 days so it shouldn't be gunked up already. I did take the needles out and fill it with carb cleaner for a little while, drained it, set the idle needle to 3/4 turn open, set the main needle to 1 1/4, took the intake hose off and fired her up..... same story :roll: ..... time to call in the reinforcements. Hopefully ol tractor Bob makes housecalls.

 

[semlin]

jerry it still could easily be the carb. don't assume that because it ran once the carb was fully cleaned out. mine did run briefly the first time i cleaned it. i figure it ran just long enough for fresh gunk to move in and reblock the passages i had just cleaned. after that it still took me multiple cleanings to finally get it good and i can tell you it took a lot more than 3 days of soaking. there are deep narrow passages and chambers in the carb casting and it clogs easily. in the end i got them clean after multiple passes using compressed air and wire.

 

[buckeyepost]

I'm kind of intimidated by the whole tearing the carb apart and putting it back together process. I don't want to mess it up even worse. If I play close attention to how things come apart and put them back together the same way will it be ok? And, what about cleaning it? Will it be fairly obvious when I have it apart what needs cleaned?

 

[RWK in WI]

It may be off the wall but - is it possible that something has blocked the air cleaner. On my TE20 I have had a mouse get into the air intake and pretty much block it. Tractor started but wanted to die. A mess to clean out - try running with oil cup off air cleaner.

 

[buckeyepost]

I thought the same thing and ran it w/ the intake hose off and it made no difference. And, I took the carb off yesterday, took it apart, cleaned it up (even though it looked fine) and put it back on today..... no change whatsoever.... that is definetely the end of my 'possible causes'... I need an old pro to look at it now, I'm totally stumped!